If the shared files of a distribution are contained in a tarball (see Dist::Zilla::Plugin::ShareDir::Tarball for why you would want to do that), automatically extract the archive in a temporary directory and return the path to that directory. If called for a regular distribution without a bundle file (shared-files.tar.gz), it'll return the original shared dir. In other words, from the consumer point of view, it'll behave just like File::ShareDir.